Remarks on the rings of functions which have a finite numb er of di scontinuities

Autor: Mohammad Reza Ahmadi Zand, Zahra Khosravi
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Applied General Topology, Vol 22, Iss 1, Pp 139-147 (2021)
Druh dokumentu: article
ISSN: 1576-9402
1989-4147
DOI: 10.4995/agt.2021.14332
Popis: Let X be an arbitrary topological space. F(X) denotes the set of all real-valued functions on X and C(X)F denotes the set of all f ∈ F(X) such that f is discontinuous at most on a finite set. It is proved that if r is a positive real number, then for any f ∈ C(X)F which is not a unit of C(X)F there exists g ∈ C(X)F such that g ≠ 1 and f = gr f. We show that every member of C(X)F is continuous on a dense open subset of X if and only if every non-isolated point of X is nowhere dense. It is shown that C(X)F is an Artinian ring if and only if the space X is finite. We also provide examples to illustrate the results presented herein.
Databáze: Directory of Open Access Journals